AVL-4000 废气分析仪系列通信协议.doc

Serial communication protocol Master/Slave 1.1 ASCII – Protocol（ASCII码协议） Each measurement value starts with a code number ( 3 characters ). You can look in the code table on the end of this document to know the value-name. The characters between the code and ETB or HT are the value with some blanks on the end. If a value is not ok we don’t send it to the PC, therefore the length of the protocol is not always constant. 每个测试值前都会有一个3个数字的代码表明其含义，客户可以在本文结尾部分的代码表中查询其具体的含义。在代码ETB或HT之间的数值其结尾可能会跟随一些空格字符。如果一个检测值不符合要求的话，仪器将不会将其传送给PC，因此协议中数据包的长度会经常变化。 1.2 Master mode（主动模式） The measurement tool send a data block to the PC. The PC have to wait for this block and send after controlling the checksum a answer ( ACK + ETB ) to our tool. 测试仪器主动传送数据到PC端，PC一直在等待数据的传送，并传送校验和检查结果（ACK+ETB）给仪器。 ACK ... checksum is OK NAK ... checksum is NOT OK, we can repeat the datablock 2 times. Parameter: （参数：） 9600 baud, 8 data bit, 1 stop bit, NO parity 2 sec timeout for RS232 Datablock - Format: （数据块-格式） AVL465 / AVL4000 -- PC STX start of data block 数据块头 nnn vvvv _ _ HT 1. Value 值 nnn vvvv _ _ HT 2. Value 值 . . . nnn vvvv _ _ HT last value 值 ‘5 ‘ ‘A ‘ 2 byte checksum ASCII 0..F ETB “ end of data block 数据块尾 nnn = ( code table 代码表 vvvv = value with some Blanks on the end 以空格结尾的值 PC -- AVL465 / AVL4000 PC test the checksum and send the answer PC端测试校验和并传送响应到仪器 ACK checksum was OK ETB or NAK checksum was not OK ETB 1.3 Slave mode ( ISOTEC - MODE) 被动模式 The PC send a question (ENQ) to the measurement tool. PC传送请求命令（ENQ）到测试仪器。 If our tool is not ready to send a data block, we answer with a NAK. 如果测试仪器没有准备好，则会响应NAK。 If our tool is ready, we send the data block. 如果测试仪器准备好了，则会传送数据块 The PC have to wait for this block and send after controlling the checksum a answer ( ACK or NAK). PC端一直等待数据块并传送数据块的校验结果（ACK/NAK）给仪器。 ACK : the checksum of the data block was OK 校验和OK if there are more than one data blocks we se